This invention relates to a generator for the production of ozone and the use of ozone for bioremediation. More particularly, an ozone generator utilizes a cryogenic oxygen source or a pulsed power supply to enhance ozone production. The ozone is used to convert volatile organic compounds in the air, liquid or the soil to innocuous compounds.
Ozone (O.sub.3) is a strong oxidizer that is used to convert harmful organic compounds into innocuous compounds. U.S. Pat. No. 4,076,617 to Bybel et al. discloses a system for the remediation of liquid waste. Ultrasonic waves break up solid particles suspended in the liquid waste and the fine particles then form an emulsion in the liquid. An ozone stream is passed through the emulsion oxidizing the organic contaminants.
In U.S. Pat. No. 4,076,617, the ozone is formed by passing dry oxygen or dry air through a corona discharge grid. The ozone yield is disclosed to be from about 3% to about 6%. The remainder of the gas recombines to form oxygen or nitrogen compounds.
U.S. Pat. No. 5,409,616 to Garbutt et al. discloses an ozone generator containing a molecular sieve to increase the oxygen content from about 20% (in ambient air) to in excess of 85% and to extract moisture from the gas. An alternating current power supply connected to a 5000 volt alternating current transformer converts the oxygen to ozone.
Both the Bybel et al. and Garbutt et al. patents are incorporated by reference in their entireties herein.
Ozone has been utilized for the bioremediation of organic compounds suspended or dissolved in a liquid medium. The ozone is bubbled through the liquid medium and, to enhance the surface area of the ozone bubbles, bubble breaking spargers have been utilized. However, to the best of our knowledge, ozone has not been successfully applied to the bioremediation of either a gaseous medium or a solid medium.
There is a need to disinfect gaseous media, such as the air in a hospital of germs and viruses or the air of a laboratory of volatile organic compounds. Presently, the air in these environments is not recirculated, but is discharged through a filter to the outside environment. This method presents the potential for releasing harmful compounds to the outside environment. Further, any energy applied to heat or cool that air is lost when the air is discharged.
Ozone has not been applied to the remediation of air because the concentration of contaminants is usually low and it has proven difficult to ensure contact between the ozone and the contaminants without providing high concentrations of ozone. High concentrations of ozone are both expensive and potentially hazardous.
Porous solids, such as soil, are usually remediated of fungi through the application of a fungicide such as dimethyl bromide. The fungicides are typically toxic. Ozone would be an environmentally sound replacement for the fungicides. The strong oxidizing of the ozone could convert the soil contaminants to relatively innocuous compounds and the ozone is unstable, so that when released to the air, it would rapidly convert to oxygen.
There remains, therefore, a need for both an ozone generator with enhanced ozone output and a mechanism to apply the ozone for the bioremediation of gaseous and porous solid media.